Integrated circuits typically include a number of input/output (I/O) pins which are used for communication with additional circuitry. For example, an integrated memory device such as a dynamic random access memory (DRAM) includes output nodes at I/O pins for bi-directional data communication with an external system or processor. Integrated circuits also typically include one or more driver circuits for driving signals on interface buses coupled to the I/O pins. Driver circuits selectively couple a supply voltage to an output node to drive an output signal on the interface bus coupled to the output node. As clock speeds increase, there is also a desire to provide the output signals more quickly to match the increase in clock speeds. Increasing the supply voltages is one way to increase transmission speeds, but this results in an undesirable increase in power consumption.